The proposed K23 Beeson Career Development Award will establish me as independent investigator focusing on research that improves the lives of older adults with heart disease. I am a board-certified geriatrician and fellow in cardiology with training in health services research. My career goal is to improve the alignment of clinical care with the diverse health needs of older adults. I have previously used administrative data to study the complexity of hospitalized patients and the clinical epidemiology of 30-day readmissions. My objective in this proposal is to integrate my interests in aging and cardiology to examine the influence of multimorbidity and geriatric impairments on 30-day readmission following hospitalization for acute myocardial infarction (AMI). Neither multimorbidity nor geriatric impairments has been integrated into models predicting readmission even though both powerfully predict adverse outcomes and 1 in 5 older adults is readmitted within 30 days of hospitalization. To study this topic, I will use an explanatory sequential mixed- methods design in which quantitative findings are further developed by qualitative analysis. In Project 1, I will examine the association of baseline multimorbidity and geriatric impairments prior to hospitalization with 30- day readmission after AMI in over 500 older adults in the Medicare Current Beneficiary Survey. I hypothesize that risk increases with baseline multimorbidity and geriatric impairments and that a model incorporating these characteristics better predicts 30-day readmission. In Project 2, I will conduct a 2-year pilot prospective study t investigate the association of changes in cognition, mobility, and function between baseline and 1 week after hospitalization on subsequent 30-day readmission in 100 older adults in the NIH-funded SILVER-AMI study. I hypothesize that it will be feasible to leverage routine follow-up visits for geriatric assessment and that initial data will show that risk of readmission is higher n patients with continued delirium and limitation in mobility and function. In Project 3, I will explre mechanisms linking multimorbidity, geriatric impairments, and readmission through in-depth interviews of 15-25 older adults readmitted within 30 days of AMI. Interviews will explore the role of delirium, new mobility and functional limitations after hospitalization, and caregiver support o 30-day readmission. Study findings will improve risk-stratification, identify key targets for intervention, and demonstrate the feasibility of using routine post-discharge visits for geriatric assessment. This proposal will broaden my methodologic expertise to include analysis of administrative data linked to geriatric assessments, primary geriatric assessments via survey and physical performance measures, in-depth interviews, and mixed methods design. I will benefit from the tutelage of exceptional mentors with expertise in aging, heart disease, hospital readmission, and multiple research methodologies. I will also attain formal research training via a Master of Science in Public Health. The resulting skills and data will establish me as a strong candidate for an R01 designed to facilitate recovery after hospitalization and lower preventable readmissions among older adults.